SpecFlow vs Cucumber comparison of testing frameworks
What are the differences between SpecFlow and Cucumber?

	SpecFlow https://specflow.org/	Cucumber https://github.com/cucumber/cucumber-ruby
Programming language	.NET	Ruby
Category	Acceptance Testing	Acceptance Testing
General info	SpecFlow is a test automation solution for .NET SpecFlow is a test automation solution for .NET which follows the BDD paradigm, and is part of the Cucumber family. SpecFlow tests are written with Gherkin, using the official Gherkin parser which allows you to write test cases using natural languages and supports over 70 languages.	An automation tool for Behavior-Driven Development The specifications are written in plain texts, which allows them to be easily understandable for all stakeholders. Cucumber Framework also supports languages beyond Ruby e.g. Java, JavaScript and Scala.
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	No	No
Client-side Allows testing code execution on the client, such as a web browser	Yes Front-end behaviour is tested. With specflow specifications of the expected behaviours are made and specflow tests against this	Yes You can test the front-end part like the GUI using cucumber and selenium, they integrate well to test your front-end.
Server-side Allows testing the bahovior of a server-side code	Yes Back-end behaviour is tested. Specifications of the expected behaviours are made and specflow tests against them	Yes You can test back-end components such as APIs using rest & soap clients, and databases using whatever client libraries were provided by the libraries that existed in those stacks
Fixtures Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test	Yes BeforeTestRun and AfterTestRun are executed once for each thread which is a limitation of the current architecture.
Group fixtures Allows defining a fixed, specific states of data for a group of tests (group-fixtures). This ensures specific environment for a given group of tests.	N/A	Yes Using the cucumber extension aruba you can create fixures in two steps: 1.Create a fixtures-directory; 2.Create fixture files in this directory
Generators Supports data generators for tests. Data generators generate input data for test. The test is then run for each input data produced in this way.	Yes SpecFlow contains a generator component. The SpecFlow IDE integration tries to locate the generator component in your project structure, in order to use the generator version matching the SpecFlow runtime in your project	Yes You can group your fixtures inside your fixtures directories
Licence Licence type governing the use and redistribution of the software	BSD license	MIT License
Mocks Mocks are objects that simulate the behavior of real objects. Using mocks allows testing some part of the code in isolation (with other parts mocked when needed)	Yes Specflow intergrates well with mock to give it excellent mocking capabilities	Yes By using all of RSpec’s supported mocking frameworks (RSpec, Mocha, RR, Flexmock)
Grouping Allows organizing tests in groups	Yes You can create test suites with specflow	Yes Cucumber allows the use of tag Cucumber feature files or individual tests to group tests. Then, you can pass a Cucumber tagged expression at test execution that specifies the tag (grouped) tests to run. https://www.toolsqa.com/cucumber/cucumber-tags/
Other Other useful information about the testing framework